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| author | Jason Zaugg <jzaugg@gmail.com> | 2013-04-24 08:57:26 +0200 |
|---|---|---|
| committer | Jason Zaugg <jzaugg@gmail.com> | 2013-04-24 12:06:30 +0200 |
| commit | 30099160320b649b1e8e5f69c8ad1b02478fbfe2 (patch) | |
| tree | 9ab2e396c7a59379208e89fcc7324a5c4f21b65b /src/compiler | |
| parent | 4dcb33e6f527f5e2bf978c9e1ca778c40bf29d54 (diff) | |
| download | scala-30099160320b649b1e8e5f69c8ad1b02478fbfe2.tar.gz scala-30099160320b649b1e8e5f69c8ad1b02478fbfe2.tar.bz2 scala-30099160320b649b1e8e5f69c8ad1b02478fbfe2.zip | |
SI-6771 Alias awareness for checkableType in match analysis.
Failure to dealias the type of the scrutinee led the pattern
matcher to incorrectly reason about the type test in:
type Id[X] = X; (null: Id[Option[Int]]) match { case Some(_) => }
Before, `checkableType` returned `Id[?]`, now it returns `Some[?]`.
Diffstat (limited to 'src/compiler')
| -rw-r--r-- | src/compiler/scala/tools/nsc/transform/patmat/MatchAnalysis.scala | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/src/compiler/scala/tools/nsc/transform/patmat/MatchAnalysis.scala b/src/compiler/scala/tools/nsc/transform/patmat/MatchAnalysis.scala index d9f93f27b6..9558542533 100644 --- a/src/compiler/scala/tools/nsc/transform/patmat/MatchAnalysis.scala +++ b/src/compiler/scala/tools/nsc/transform/patmat/MatchAnalysis.scala @@ -99,7 +99,9 @@ trait TreeAndTypeAnalysis extends Debugging { // TODO: when type tags are available, we will check -- when this is implemented, can we take that into account here? // similar to typer.infer.approximateAbstracts object typeArgsToWildcardsExceptArray extends TypeMap { - def apply(tp: Type): Type = tp match { + // SI-6771 dealias would be enough today, but future proofing with the dealiasWiden. + // See neg/t6771b.scala for elaboration + def apply(tp: Type): Type = tp.dealiasWiden match { case TypeRef(pre, sym, args) if args.nonEmpty && (sym ne ArrayClass) => TypeRef(pre, sym, args map (_ => WildcardType)) case _ => |